Mobile Pump System

ABSTRACT

A mobile pump system includes: a trailer movable by a vehicle; a first pump and a second pump mounted to the trailer and in fluid communication with an outlet configured to flow a fluid to a destination and with a fluid source; a power source mounted to the trailer and directly coupled to the first pump and/or the second pump, where the power source includes a turbine and/or a natural gas fired reciprocating engine; and a control system configured to: activate the second pump, with the first pump deactivated, with a flow rate of the mobile pump system below a first set point; in response to the flow rate of the mobile pump system reaching the first set point, activate the first pump; and deactivate the second pump, with the first pump activated, in response to the flow rate of the mobile pump system reaching a second set point, where the second set point is greater than or equal to the first set point.

BACKGROUND 1. Field

The present disclosure relates to a mobile pump system and a method forperforming a pressure pumping application including the mobile pumpsystem.

2. Technical Considerations

Pressure pumping includes a propagation of fractures through layers ofrock using pressurized fluid and/or pumping cement into a wellbore tocomplete it.

In one non-limiting example of pressure pumping, to extract oil and/orgas trapped in formations beneath the Earth's surface, drilling of awellbore is required, and the oil and/or gas may be recovered andextracted through the wellbore. Various pumps may be used during thedrilling and oil and/or gas recovery process.

In some non-limiting oilfield applications, drilling may include forminghorizontal laterals extending out from a vertical section of thewellbore. The formation defining the vertical or lateral section may befractured in sections, such that a fracture stimulation treatment iscompleted in the first section before moving on to apply a fracturestimulation treatment on a second section. This may be performed using aplug-and-perf technique in which a perforating gun is used to initiatefractures in the formation in the section after a plug is positionedbetween the first section and the second section. The plug seals thefirst section of the lateral from the other sections. This plug-and-perftechnique is repeated for each section of the lateral until all intendedsections of the lateral are perforated and fracture stimulated.

The plug may be positioned at a predetermined location along the lateralby utilizing a pump system to pump a fluid into the wellbore, whichexerts a pressure on the plug. The pressure on the plug moves the plugalong the lateral to the desired position. Positioning the plug usingthe pump is considered an ancillary application, commonly referred to as“pumpdown”.

Existing pumps used in pressure pumping application, such as inancillary pumpdown applications have numerous drawbacks. For example,existing pumps use an internal combustion engine driven by diesel fuel,which have high carbon footprints. In addition, these existing pumps arecumbersome and require considerable room at the well site. Further,these existing pumps do not allow for sufficiently precise control offlow rate, making it difficult to move the plug to the desired position.Existing pumps are expensive to acquire and maintain, and they createsignificant noise at a decibel level that is known to harm human hearingwithout adequate ear protection.

Further, existing pumping systems utilized in pressure pumpingapplications, including ancillary pressure pumping applications, are notcapable of sufficiently low flow rates or precise control of the flowrate or pump pressure. The existing pump systems lack precise controland the ability to operate at lower flow rates because they utilizeconventional transmissions that are incapable of smooth increase ordecrease in pumping rates. This may be the result of hesitation andslugging common when primary gears disengage and engage the secondaryshaft. As a result, existing pressure pumping systems do not effectivelyremedy screen outs occurring during hydraulic fracturing applications.

Further, higher rates may oftentimes be required for certain pumpingapplications. Many existing single pump systems are required to belocated at a well site which take up considerable room, therebyaffecting the standards of safety with increased personnel and moretreating equipment like hoses and high pressure treating irons,affecting the cost of the well pad and causing large expenditures inconstruction of the well pad to accommodate the multiple pumpingsystems, and requiring increased amounts of diesel fuel to be trucked tolocation and dispersed among the pumps as they are engaged in highpressure and/or high rate operations.

Further, existing pumping systems utilized in pressure pumpingapplications are costly to build and to operate. Traditionaldiesel-powered pumps require regular repair and maintenance which caninflate operational costs. Diesel is a comparatively expensive fuel andis a cause of a variety of pollutants and greenhouse gases when burnedwhen compared to an alternate fuel source like natural gas, and dieselengines also require certain maintenance that leads to significant wastestreams and monetary expenditure being required.

Therefore, a pump suitable for pressure pumping applications thatovercomes some or all of the disadvantages of existing pumps is desired.

SUMMARY

The present disclosure is directed to a mobile pump system including: atleast one trailer movable by a vehicle; a plurality of pumps including afirst pump and a second pump, where the first pump and the second pumpare each mounted to the at least one trailer, where the first pump andthe second pump are each in fluid communication with an outletconfigured to flow a fluid from the mobile pump system to a destinationand with a fluid source configured to hold a pumping fluid; a powersource mounted to the at least one trailer and directly coupled to thefirst pump and/or the second pump, where the power source includes aturbine and/or a natural gas fired reciprocating engine; and a controlsystem configured to: activate the second pump, with the first pumpdeactivated, with a flow rate of the mobile pump system below a firstset point to cause the second pump to pump the pumping fluid; inresponse to the flow rate of the mobile pump system reaching the firstset point, activate the first pump to cause the first pump to pump thepumping fluid; and deactivate the second pump, with the first pumpactivated, in response to the flow rate of the mobile pump systemreaching a second set point, where the second set point is greater thanor equal to the first set point.

The first pump may configured to pump fluid at a flow rate as low as 2.5bpm and at a flow rate of up to 30 bpm, and the second pump may beconfigured to pump fluid a flow rate as low as 0.1 bpm. The first pumpmay include a multi-stage centrifugal injection pump. The first pump mayinclude a pressure-balanced pump. The second pump may include a positivedisplacement pump. The positive displacement pump may be a reciprocatingtriplex or quintuplex pump. The control system may include an electronicgovernor configured to control at least one of a rotational speed of thepower source, a flow rate of the first pump and/or the second pump, anda pumping pressure of the first pump and/or the second pump. Theelectronic governor may be configured to adjust the flow rate of thefirst pump and/or the second pump by an incremental amount as low as 0.1bpm. The power source may be directly coupled to the first pump, wherethe direct coupling may include a non-variable, fixed ratiodirect-coupled connection or a direct-coupled gear connection includinga speed reducer. The second pump may be powered by an electric motorreceiving power generated by the power source. The control system may beconfigured to initiate a start-up protocol by: activating the secondpump, with the first pump deactivated, until the flow rate of the mobilepump system is at least 1.5 bpm; and activating the first pump, whilethe second pump is still activated, once the flow rate of the mobilepump system is at the first set point, where the first set point is atleast 1.5 bpm. The mobile pump system may not be permanently installedat a site for performing a pressure pumping application. The powersource may be operated using field gas. The first pump and/or the secondpump may be configured to pump fluid at a pressure of 15,000 psi orgreater. The mobile pump system may include a fluid storage tank mountedto the at least one trailer and a third pump mounted to the at least onetrailer and in fluid communication with the fluid storage tank, thefirst pump, and the second pump, where the third pump is configured topump fluid from the fluid storage tank to the first pump and/or thesecond pump. The pumping fluid may be pumped to the outlet by the secondpump and not the first pump with the flow rate of the mobile pump systembelow the first set point, and the pumping fluid may be pumped to theoutlet by the first pump and optionally the second pump with the flowrate of the mobile pump system at or above the first set point.

The present disclosure is also directed to a method for performing apressure pumping application, including positioning a mobile pump systemon a pump site. The mobile pump system includes: at least one trailermovable by a vehicle; a plurality of pumps including a first pump and asecond pump, where the first pump and the second pump are each mountedto the at least one trailer, where the first pump and the second pumpare each in fluid communication with an outlet configured to flow afluid from the mobile pump system to a destination and with a fluidsource configured to hold a pumping fluid; a power source mounted to theat least one trailer and directly coupled to the first pump and/or thesecond pump, where the power source includes a turbine and/or a naturalgas fired reciprocating engine; and a control system configured to:activate the second pump, with the first pump deactivated, with a flowrate of the mobile pump system below a first set point to cause thesecond pump to pump the pumping fluid; in response to the flow rate ofthe mobile pump system reaching the first set point, activate the firstpump to cause the first pump to pump the pumping fluid; and deactivatethe second pump, with the first pump activated, in response to the flowrate of the mobile pump system reaching a second set point, where thesecond set point is greater than or equal to the first set point.

The method may include activating the second pump, with the first pumpdeactivated, until the flow rate of the mobile pump system is at least1.5 bpm; and activating the first pump, while the second pump is stillactivated, once the flow rate of the mobile pump system is at the firstset point, where the first set point is at least 1.5 bpm. The method mayinclude deactivating the second pump, while the first pump is stillactivated, once the flow rate flow rate of the mobile pump system is atthe second set point. The method may include positioning a plug in alateral of a wellbore using fluid pumped into the wellbore via themobile pump system. The method may include performing, using the mobilepump system, a toe prep application, a drill-out application, anindustrial purging application, a pipeline pressure testing application,and/or a hydro-blasting application.

Further embodiments are set forth in the following numbered clauses:

Clause 1: A mobile pump system, comprising: at least one trailer movableby a vehicle; a plurality of pumps comprising a first pump and a secondpump, wherein the first pump and the second pump are each mounted to theat least one trailer, wherein the first pump and the second pump areeach in fluid communication with an outlet configured to flow a fluidfrom the mobile pump system to a destination and with a fluid sourceconfigured to hold a pumping fluid; a power source mounted to the atleast one trailer and directly coupled to the first pump and/or thesecond pump, wherein the power source comprises a turbine and/or anatural gas fired reciprocating engine; and a control system configuredto: activate the second pump, with the first pump deactivated, with aflow rate of the mobile pump system below a first set point to cause thesecond pump to pump the pumping fluid; in response to the flow rate ofthe mobile pump system reaching the first set point, activate the firstpump to cause the first pump to pump the pumping fluid; and deactivatethe second pump, with the first pump activated, in response to the flowrate of the mobile pump system reaching a second set point, wherein thesecond set point is greater than or equal to the first set point.

Clause 2: The mobile pump system of clause 1, wherein the first pump isconfigured to pump fluid at a flow rate as low as 2.5 or 1.5 bpm and ata flow rate of up to 30 bpm, and wherein the second pump is configuredto pump fluid a flow rate as low as 0.1 bpm.

Clause 3: The mobile pump system of clause 1 or 2, where the first pumpcomprises a multi-stage centrifugal injection pump.

Clause 4: The mobile pump system of any of clauses 1-3, wherein thefirst pump comprises a pressure-balanced pump.

Clause 5: The mobile pump system of any of clauses 1-4, wherein thesecond pump comprises a positive displacement pump.

Clause 6: The mobile pump system of clause 5, wherein the positivedisplacement pump is a reciprocating triplex or quintuplex pump.

Clause 7: The mobile pump system of any of clauses 1-6, wherein thecontrol system comprises an electronic governor configured to control atleast one of a rotational speed of the power source, a flow rate of thefirst pump and/or the second pump, and a pumping pressure of the firstpump and/or the second pump.

Clause 8: The mobile pump system of clause 7, wherein the electronicgovernor is configured to adjust the flow rate of the first pump and/orthe second pump by an incremental amount as low as 0.1 bpm.

Clause 9: The mobile pump system of any of clauses 1-8, wherein thepower source is directly coupled to the first pump, wherein the directcoupling comprises a non-variable, fixed ratio direct-coupled connectionor a direct-coupled gear connection including a speed reducer.

Clause 10: The mobile pump system of any of clauses 1-9, wherein thesecond pump is powered by an electric motor receiving power generated bythe power source.

Clause 11: The mobile pump system of any of clauses 6-10, wherein thecontrol system is configured to initiate a start-up protocol by:activating the second pump, with the first pump deactivated, until theflow rate of the mobile pump system is at least 1.5 bpm; and activatingthe first pump, while the second pump is still activated, once the flowrate of the mobile pump system is at the first set point, wherein thefirst set point is at least 1.5 bpm.

Clause 12: The mobile pump system of any of clauses 1-11, wherein themobile pump system is not permanently installed at a site for performinga pressure pumping application.

Clause 13: The mobile pump system of any of clauses 1-12, wherein thepower source is operated using field gas.

Clause 14: The mobile pump system of any of clauses 1-13, wherein thefirst pump and/or the second pump are configured to pump fluid at apressure of 15,000 psi or greater.

Clause 15: The mobile pump system of any of clauses 1-14, furthercomprising a fluid storage tank mounted to the at least one trailer anda third pump mounted to the at least one trailer and in fluidcommunication with the fluid storage tank, the first pump, and thesecond pump, wherein the third pump is configured to pump fluid from thefluid storage tank to the first pump and/or the second pump.

Clause 16: The mobile pump system of any of clauses 1-15, wherein thepumping fluid is pumped to the outlet by the second pump and not thefirst pump with the flow rate of the mobile pump system below the firstset point, and the pumping fluid is pumped to the outlet by the firstpump and optionally the second pump with the flow rate of the mobilepump system at or above the first set point.

Clause 17: A method for performing a pressure pumping application,comprising: positioning the mobile pump system of any of clauses 1-16 ona pump site.

Clause 18: The method of clause 17, further comprising: activating thesecond pump, with the first pump deactivated, until the flow rate of themobile pump system is at least 1.5 bpm; and activating the first pump,while the second pump is still activated, once the flow rate of themobile pump system is at the first set point, wherein the first setpoint is at least 1.5 bpm.

Clause 19: The method of clause 18, further comprising: deactivating thesecond pump, while the first pump is still activated, once the flow rateflow rate of the mobile pump system is at the second set point.

Clause 20: The method of any of clauses 17-19, further comprising:positioning a plug in a lateral of a wellbore using fluid pumped intothe wellbore via the mobile pump system.

Clause 21: The method of any of clauses 17-20, further comprising:performing, using the mobile pump system, a toe prep application, adrill-out application, an industrial purging application, a pipelinepressure testing application, and/or a hydro-blasting application.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional advantages and details are explained in greater detail belowwith reference to the exemplary embodiments that are illustrated in theaccompanying schematic figures, in which:

FIG. 1 shows a schematic cross-sectional view of the Earth at an oiland/or gas production site utilizing horizontal drilling techniques;

FIG. 2 shows another schematic cross-sectional view of the Earth at anoil and/or gas production site utilizing horizontal drilling techniquesand a mobile pump system;

FIG. 3 shows a schematic aerial view of a well pad at an oil and/or gasproduction site, the well pad including a mobile pump system;

FIG. 4 shows a schematic side view of a mobile pump system including atrailer and a cab for moving the mobile pump system;

FIG. 5 shows a schematic top view of a mobile pump system including thetrailer and the electrically-driven pump or turbine-driven pump;

FIG. 6 shows a schematic side view of an auger-style pump of a mobilepump system;

FIG. 7 shows a controller for controlling a mobile pump system;

FIG. 8 shows a schematic top view of a mobile pump system including apump driven by an electric motor;

FIG. 9 shows a schematic perspective view of a mobile pump systemincluding a pump driven by a turbine and/or a natural gas firedreciprocating engine;

FIG. 10 shows a schematic perspective view of a mobile pump systemincluding a pump driven by a turbine and/or a natural gas firedreciprocating engine, with the trailer including a fuel tank;

FIG. 11 shows a schematic top view of a mobile pump system including asecondary pump;

FIG. 12 shows a schematic side view of a mobile pump system includingmultiple pumps and a turbine and/or a natural gas fired reciprocatingengine;

FIG. 13 shows a schematic top view of a mobile pump system includingmultiple pumps and a turbine and/or a natural gas fired reciprocatingengine;

FIG. 14 shows a cross-sectional view of a non-limiting example of thefirst pump being a multi-stage centrifugal injection pump;

FIG. 15 shows a cross-sectional view of a non-limiting example of thesecond pump being a positive displacement triplex or quintuplex pump;

FIG. 16 shows a cross-sectional view of a non-limiting example of theturbine and/or a natural gas fired reciprocating engine including aspeed reducer; and

FIG. 17 shows a side view of a non-limiting example of the second pumpbeing a positive displacement triplex or quintuplex pump.

DETAILED DESCRIPTION

For purposes of the description hereinafter, the terms “end,” “upper,”“lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,”“lateral,” “longitudinal,” and derivatives thereof shall relate to theinvention as it is oriented in the drawing figures. However, it is to beunderstood that the invention may assume various alternative variationsand step sequences, except where expressly specified to the contrary. Itis also to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification, are simply exemplary embodiments or aspects of theinvention. Hence, specific dimensions and other physical characteristicsrelated to the embodiments or aspects disclosed herein are not to beconsidered as limiting.

No aspect, component, element, structure, act, step, function,instruction, and/or the like used herein should be construed as criticalor essential unless explicitly described as such. Also, as used herein,the articles “a” and “an” are intended to include one or more items andmay be used interchangeably with “one or more” and “at least one.”

The present disclosure is directed to a mobile pump system thatincludes: a trailer movable by a vehicle; and a pump mounted to thetrailer, the pump configured to pump a fluid, wherein the pump comprisesan electrically-driven motor mounted to the trailer or is turbinepowered by a turbine mounted to the trailer. The mobile pump systemdescribed herein may be suitable for pressure pumping applications.

The present disclosure is also directed to a mobile pump system,comprising: at least one trailer movable by a vehicle; a plurality ofpumps comprising a first pump and a second pump, wherein the first pumpand the second pump are each mounted to the at least one trailer,wherein the first pump and the second pump are each in fluidcommunication with an outlet configured to flow a fluid from the mobilepump system to a destination and with a fluid source configured to holda pumping fluid; a power source mounted to the at least one trailer anddirectly coupled to the first pump and/or the second pump, wherein thepower source comprises a turbine and/or a natural gas firedreciprocating engine; and a control system configured to: activate thesecond pump, with the first pump deactivated, with a flow rate of themobile pump system below a first set point to cause the second pump topump the pumping fluid; in response to the flow rate of the mobile pumpsystem reaching the first set point, activate the first pump to causethe first pump to pump the pumping fluid; and deactivate the secondpump, with the first pump activated, in response to the flow rate of themobile pump system reaching a second set point, wherein the second setpoint is greater than or equal to the first set point.

Referring to FIG. 1, an oil and/or gas production site 10 is shown. Atthe production site 10, the surface 11 (Earth's surface) includeswellbore 12 created by drilling. The wellbore 12 includes a wellhead 13,which is a structural component at the surface 11 of the wellbore 12which provides a structural and pressure-containing interface forvarious drilling and production equipment. The production site 10 may bea site for conducting hydraulic fracturing.

With continued reference to FIG. 1, the production site 10 may utilize ahorizontal drilling technique in which at least one lateral 14 is used.For the horizontal drilling technique, the wellbore 12 may include avertical region of 2,500 to 25,000, such as 6,000 to 15,000 or 6,000 to10,000 feet in depth, although the length of this vertical region is notlimited to this range. The wellbore 12 may include a leveling-off point16 in which the vertical region ends and the lateral 14 is drilledhorizontally in the Earth (the lateral 14 may have approximately thesame depth from the surface 11 at all points). Each lateral 14 may havea length of 2,500-25,000, such as 3,000 to 10,000 feet, as measured fromthe leveling-off point 16 to an end 18 of the lateral 14, although thelength of the lateral 14 is not limited to this range. It will beappreciated that FIG. 1 is not drawn to scale, but merely provides auseful schematic of a production site 10 performing horizontal drilling.

The lateral 14 may include a plurality of regions, which are of apredetermined length. Hydraulic fracture stimulation treatment may beperformed in the lateral 14 individually at each region. Hydraulicfracture stimulation treatment includes pumping a fracturing fluid intothe formation. The lateral 14 of the schematic in FIG. 1 includes afirst region 20, a second region 22, a third region 24, a fourth region26, a fifth region 28, and a sixth region 30.

With continued reference to FIG. 1, the production site 10 may utilize a“plug-and-perf” method for hydraulic fracture stimulation treatment. InFIG. 1, hydraulic fracture stimulation treatment has been completed forthe first region 20. A fractured first region 32 was created in theformation at the first region 20. After the hydraulic fracturestimulation treatment was completed in the first region 20, a first plug34 was positioned at an end of the first region 20 closest to thewellhead 13 (a proximal end of the first region 20). Once in place, thisfirst plug 34 may prevent fluid subsequently pumped into the wellbore 12from entering the first region 20.

With continued reference to FIG. 1, hydraulic fracture stimulationtreatment in the second region 22 of the formation may be initiated bylowering a perforating gun 36 (hereinafter “perf gun”) into the wellbore12 and positioning the perf gun 36 in the second region 22. The perf gun36 may be lowered into the wellbore 12 using a perf trailer 37. Oncepositioned correctly, charges of the perf gun 36 may be detonated so asto create multiple connection points from the wellbore 12 to theformation in the second region 22. Oil and/or gas may be extracted byescaping from fractures and extracted to the surface 11 via the wellbore12.

Referring to FIG. 2, the production site 10 is shown at a time afterthat depicted in FIG. 1. The fractured second region 38 is shown, whichwas created by the perf gun 36 from FIG. 1. It will be appreciated thatFIG. 2 is also not drawn to scale, but merely provides a usefulschematic of a production site 10 performing horizontal and/or verticaldrilling.

In FIG. 2, a second plug 40 is being lowered into the wellbore 12 by aplug trailer 41 to be positioned at a proximal position of the secondregion 22 (on the end of the second region 22 closer to the wellhead13). The second plug 40 is spaced apart from the first plug 34 byapproximately the length of the second region 22. The second plug 40 maybe positioned using positioning fluid 42 to provide pressure to thesecond plug 40 to move the second plug along the length of the wellbore12 (including the lateral 14). The positioning fluid 42 may includewater and/or a chemical additive. The chemical additive may include afriction reducer to reduce surface tension. The chemical additive mayreduce tension or pipe friction along the wellbore 12 associated withpositioning the second plug 40.

The second plug 40 may be positioned using the mobile pump system 44 ofthe present disclosure. The mobile pump system 44 may be used toposition the second plug 40 as merely one non-limiting example of howthe mobile pump system 44 may be used in a pressure pumping application.However, it will be appreciated that the mobile pump system 44 may beused to complete other pressure pumping applications using thecomponents of the mobile pump system 44 described hereinafter.

The mobile pump system 44 may include a trailer 46 movable by a vehicle(e.g., a cab having a fifth wheel). The trailer 46 may be movable by avehicle, such as a cab, to and from the production site 10. In this way,the mobile pump system 44 may be conveniently moved from location tolocation, such as to and from the production site 10, and the mobilepump system 44 does not need to be permanently installed at theproduction site 10. The trailer 46 may be separable/detachable from thevehicle such that the trailer 46 may be left at the production site 10and the vehicle driven away, or the trailer 46 may be integrated withthe vehicle, such that the vehicle remains at the production site 10while the mobile pump system 44 is in use and drives away after use ofthe mobile pump system 44 is completed.

With continued reference to FIG. 2, the mobile pump system 44 mayfurther include at least one pump 48 mounted to the trailer 46. The atleast one pump 48 may be configured to pump the positioning fluid 42into the wellbore 12. The at least one pump 48 may include an electricmotor 50 mounted to the trailer 46 or may be powered by a turbine and/ora natural gas fired reciprocating engine 50 mounted to the trailer 46.The trailer 46 may include multiple pumps 48 in some embodiments and mayinclude multiple electric motors and/or turbines and/or natural gasfired reciprocating engine 50 for driving the pumps 48. As used herein,the term “electric motor” or “electrically-driven motor” refers to amotor in which electrical energy is converted into mechanical energy. Asused herein, the term “turbine” refers to a rotary mechanical devicethat extracts energy from a fluid (e.g., liquid and/or gas) flow andconverts it into useful work. The trailer 46 may also include a powergenerator 52 in connection with the at least one pump 48 to fuel theelectrically-driven motor or the turbine 50 of the at least one pump 48.The power generator 52 may be battery, natural gas, diesel fuel, orgasoline fueled. The at least one pump 48 may be driven by the electricmotor or the turbine 50 and not by an internal combustion engine. Thepump 48 may be driven by a natural gas fired reciprocating engine.

The at least one pump 48 may be configured to pump the positioning fluid42, or any other fluid, at a flow rate of up to 30 barrels per minute(bpm), such as up to 60 bpm, up to 80 bpm, up to 100 bpm, up to 120 bpm,up to 140 bpm or higher. A barrel is defined as 42 US gallons, which isapproximately 159 Liters. The at least one pump 48 may be configured topump the positioning fluid 42 at far lower flow rates, and may pump thepositioning fluid 42 at a flow rate as low as 0.1 bpm (when the pump isnot turned off such that it's flow rate would be 0 bpm). The at leastone pump 48 may be controlled such that its flow rate may be controlledwithin 0.1 bpm, resulting in a flow rate within 0.1 bpm compared to apredetermined flow rate. The pump may be configured to adjust the flowrate by 0.1 bpm (e.g., adjust the flow rate of the at least one pump 48from 60.0 bpm to 59.9 bpm or from 0.2 bpm to 0.1 bpm). Existing pressurepumping systems, including ancillary pressure pumping applications, arenot capable of such low flow rates or such precise control of the flowrate. The existing pump systems lack precise control and the ability tooperate at lower flow rates because they utilize conventionaltransmissions that are incapable of smooth increase or decrease inpumping rates. This may be the result of hesitation and slugging commonwhen primary gears disengage and engage the secondary shaft.

The ability to pump at lower rates and to more precisely control theflow rate of the at least one pump 48 may be especially useful inpost-occurrence remedying of “screen outs,” which are common inhydraulic fracturing applications. A screen out occurs when proppant andfluid (of the positioning fluid 42, for example) can no longer beinjected into the formation. This may be due to resistant stresses ofthe formation becoming too excessive or surface-originated reasonsresulting in loss of viscosity to carry proppant so that it falls out ofsuspension and plugs perforations in the wellbore 12. In this way, thewellbore 12 becomes “packed” with proppant, which does not allow anyfurther operations to continue due to high pressures that cannot beovercome from these blockages.

In response to screen outs, the wellbore 12 may be opened at the surface11 to relieve pressure and to carry at least some of the proppant out ofthe wellbore 12 and create a pathway to continue fluid injection toclear the wellbore 12 and allow operations to continue, which is adangerous operation. An attempt to continue pumping operations at lowrates to avoid reaching maximum pressure so that the proppant that ispacked is forced through perforations and into the wellbore 12 may beattempted. However, due to the limitations of existing pumps withconventional engines and transmissions, the pump cannot pump at lowenough rates to avoid again reaching maximum pressure. As a result,existing systems are often required to switch to a coiled tubingprocedure to wash the proppant out and carry it back to the surface sothat the wellbore 12 is finally clear. The coiled tubing procedureresults in shutdown of operations for 3-4 days and is additionallyexpensive to complete.

In contrast to existing systems, the mobile pump system 44 is able toovercome these screen outs successfully without reverting to the coiledtubing procedure because the electric motor and/or the turbine and/orthe natural gas fired reciprocating engine 50 of the at least one pump48 allows the at least one pump 48 to inject fluid for displacement atlower rates (as low as 0.1 bpm) over the course of hours or days withoutthe risks posed by existing systems.

The ability to pump fluids at lower rates and to more precisely controlthe flow rate of the at least one pump 48 may be especially useful inprevention or mitigation of the adiabatic effect which can causewireline cable melting and/or failure during pumpdown operations, whichare common in hydraulic fracturing applications. On pumpdowns andrelated jobs involving wireline operations with pump assist, thewellhead is equipped with a lubricator and flow tubes to enableoperations in a wellbore that can have pressure of several thousandpounds or more of pressure. The process of bringing the lubricator andthe wellbore to the same pressure is known as “equalization.” When theair in the lubricator compresses faster than it can be evacuated, theadiabatic compression can cause the temperature to rise to as much as1,200° F. (˜650° C.). At high temperatures, the insulating material ofthe cable would melt and the metallurgy of the steel in the cable wouldchange, causing the actual wire in the wireline to become brittle andbreak, even to the point of severing the wireline within the lubricator.A common name for this condition is “wireline burn up” though othercolloquialisms and phrases (such as “E-line burn”) describe the samecondition.

In practice, to avoid wireline burn-up, the lubricator may first befilled with fluid prior to equalizing; this practice can mitigate muchof the air and therefore most of the energy to cause damage. In order tofill the lubricator with fluid without inducing wireline burn-up, thefluid must be introduced at very low rates so that the air can beevacuated at an equivalent rate so as not to introduce temperatureincreases caused by compressing air rapidly. However, due to thelimitations of existing pump systems with conventional engines andtransmissions, the pump cannot pump at low enough rates to completelyavoid against reaching damaging high temperatures. In contrast, the atleast one pump 48 would be able to overcome this situation successfullybecause the electric motor and/or the turbine and/or the natural gasfired reciprocating engine 50 of the at least one pump 48 allows the atleast one pump 48 to inject fluid for displacement of the air in thelubricator at lower rates (as low as approximately 0.1 bpm) without therisks posed by existing systems.

The at least one pump 48 may be configured to pump fluid at a pressureof up to 20,000 psi, such as up to 15,000 psi, up to 12,000 psi, up to10,000 psi, up to 8,000 psi, or up to 6,000 psi, although higherpressures are also contemplated.

With continued reference to FIG. 2, a fluid tank 54 containing thepositioning fluid 42 may be in fluid communication with the at least onepump 48. The at least one pump 48 may pump the positioning fluid 42 fromthe fluid tank 54 into the wellbore 12 to position the second plug 40 ata predetermined position in the wellbore 12.

With continued reference to FIG. 2, the mobile pump system 44 mayposition the second plug 40 at a predetermined position in the wellbore12. The second plug 40 may be positioned in the wellbore by providingthe previously-described mobile pump system 44. The at least one pump 48of the mobile pump system 44 may be placed in fluid communication withthe wellbore 12. The positioning fluid 42 may be pumped from the fluidtank 54 into the wellbore 12 using the at least one pump 48. Thepositioning fluid 42 pumped into the wellbore 12 may exert a pressure onthe second plug 40 so as to move the second plug 40 along the lateral 14and into the predetermined position. The position of the second plug 40may be monitored from the surface by any means known in the art. Theflow rate of the positioning fluid 42 pumped by the at least one pump 48may be adjusted and controlled to position the second plug 40. The flowrate may be increased or decreased to adjust the rate at which thesecond plug 40 is moved. For example, when the second plug 40 isproximate the predetermined position, the flow rate of positioning fluid42 may be lowered so that the position of the second plug 40 can be moreprecisely selected.

The mobile pump system 44 described herein may be used for any pressurepumping in which its characteristics are suitable and is not limited tothe above-described application. For example, the mobile pump system 44may be used in hydraulic fracturing applications. Hydraulic fracturingapplications include any application associated with hydraulicfracturing performed at a production site. Hydraulic fracturing refersto fluid injected down the wellbore through perforations exceeding theminimum fracture pressure needed to fracture the rock in the formation.An example of a hydraulic fracturing application includes ancillaryapplications (“pumpdown”), such as positioning a plug (previouslydescribed), drillout applications, injecting acid into the formation,pressure testing casing, injecting diverter materials, “toe preps”involving initiating the first fracture network in a well, and the like.Drillout applications may include applications performed after thedrilling and fracturing process has concluded and the well is beingprepared to deliver hydrocarbon production. As one example, a drilloutapplication may include milling or drilling out plugs previouslypositioned in the laterals and removing debris from the milled plugs bypumping the debris from the plug location to the surface.

The mobile pump system 44 allows for the reduction of capital costscompared to existing pump systems as the mobile pump system 44 requiresless capital costs to build and operate. The mobile pump system 44 alsosignificantly reduces repair and maintenance costs compared to existingsystems. The use of the electric motor and/or turbine and/or natural gasfired reciprocating engine 50 to drive the at least one pump 48 helps toreduce repair and maintenance costs. The electric motor and/or turbineand/or natural gas fired reciprocating engine 50 has a higher run timebefore requiring repairs compared to conventional internal combustiondiesel engines (motors) used in existing pumps, which are diesel driven,for example. Keeping the electric motor and/or turbine and/or naturalgas fired reciprocating engine 50 cool and lubricated allows theelectric motor and/or turbine and/or natural gas fired reciprocatingengine 50 to have a longer running life compared to the motors used inexisting systems. The electric motor and/or turbine and/or natural gasfired reciprocating engine 50 also run more efficiently compared to themotors used in existing systems, such as in terms of emissions andconsumption of fuel.

The mobile pump system 44 using the electric motor and/or turbine and/ornatural gas fired reciprocating engine 50 to drive the at least one pump48 also requires significantly less fuel, monetary expenditure tomaintain, and results in less environmental waste from maintenance,compared to existing systems. The electric motor and/or turbine and/ornatural gas fired reciprocating engine 50 may utilize naturalgas-powered electric generation, such as the field gas available at aproduction site. Thus, sulfur and other pollutants that arise fromdiesel combustion in conventional internal combustion motors are notpresent in the combustion of natural gas powered electric generation.The inclusion of the electric motor and/or the turbine and/or thenatural gas fired reciprocating engine 50 in the mobile pump system 44also reduces the noise associated with the mobile pump system 44 aspumps used in existing systems provide significant noise pollution andmake it difficult to operate such pumps in residential areas (e.g., nearhousing plans, schools, hospitals, and the like).

The mobile pump system 44 includes a more compact design of the pumps 48compared with existing systems. Multiple pumps 48 may be included on thetrailer 46. The more compact system contributes to a safer productionsite 10 as there are less components at the production site 10 to causea navigational and/or tripping hazard. This compact design also allowsfor the mobile pump system 44 to be set-up faster, resulting in lesswasted time and faster time to production. Moreover, the mobile pumpsystem 44 may include multiple of at least one component included in thesystem, such as multiple pumps 48, multiple electric motors and/orturbines and/or natural gas fired reciprocating engines 50, multiplecontrollers 80, and the like. The redundancy associated with certain ofthe components mounted on the trailer 46 of the mobile pump system 44allows the system to avoid stopping operation of the pressure pumpingapplication should one of the redundant components fail.

Referring to FIG. 3, an aerial view of the production site 10 is shown.The production site 10 includes a well pad 56. The well pad 56 includessix wellbores 12A-12F, each wellbore having a vertical region and atleast one lateral traversing a direction different from the otherwellbores of the well pad 56. In the schematic in FIG. 3, thenon-limiting example of a pressure pumping application is beingconducted at only the first wellbore 12A; however, multiple well headsmay be in production (e.g., conducting oilfield activity)simultaneously.

The production site 10 may include at least one fracturing trailer58A-58F, each including at least one fracturing pump 60A-60F. Theproduction site 10 may further include sand and fracturing fluid storagetanks 62, which include sand and fracturing fluid used to keep fracturesin the formation open. The production site 10 may further include awater tank 64 for pumping water into the first wellbore 12A. The watertank 64 may be in addition to or the same as the fluid tank 54containing the positioning fluid 42. The production site 10 may furtherinclude a chemical storage tank 66, which may store any useful chemical,such as a friction reducer (e.g., polyacrylamide or a guar-basedchemical). The fracturing pumps 60A-60F may be in fluid communicationwith at least one of the sand and fracturing fluid storage tanks 62, thewater tank 64, and the chemical storage tank 66 to pump the variousmaterials and/or fluids contained therein into the first wellbore 12Avia piping 70. The piping 70 may include an isolation valve 72 forisolating the fracturing pumps 60A-60F from the first wellbore 12A whenthe fracturing pumps 60A-60F are not pumping fluid/material into thefirst wellbore 12A.

With continued reference to FIG. 3, the production site 10 may furtherinclude a data monitoring station 68, which may be used to monitor alloperations conducted at the production site 10 and control thoseoperations accordingly. In some non-limiting examples, the datamonitoring station 68 may be remote from the production site 10.

With continued reference to FIG. 3, production site 10 may furtherinclude the mobile pump system 44A. The production site may include asingle mobile pump system 44A or multiple mobile pump systems 44A-44B,as necessary. In the non-limiting example of FIG. 3, a first mobilepumping system 44A is used to pump positioning fluid 42 into the firstwellbore 12A. The first mobile pumping system 44A may include a firsttrailer 46A, a first power generator 52A, and a first pump 48A having afirst electric motor 50A. The production site 10 may utilize a secondmobile pumping system 44B in addition to or in lieu of the first mobilepumping system 44A. The second mobile pumping system 44B may include asecond trailer 46B, a second power generator 52B, and two pumps 48B,48C, each having an electric motor and/or turbine and/or natural gasfired reciprocating engine 50B, 50C. The production site 10 may includethe fluid tank 54 containing the positioning fluid 42, and the fluidtank 54 may be in fluid communication with the first pump 48A of thefirst mobile pumping system 44A. The first mobile pumping system 44A andthe second mobile pumping system 44B may be moved to and from theproduction site 10 without being permanently installed at the pumpingsite 10.

With continued reference to FIG. 3, the first pump 48A may be in fluidcommunication with the first wellbore 12A so as to pump the positioningfluid 42 into the first wellbore 12A. The first pump 48A may be in fluidcommunication with the piping 70 so as to be in fluid communication withthe first wellbore 12A, and the first pump 48A may intersect with thepiping 70 at a tie-in point 74. The tie-in point 74 may be upstream ofthe wellhead of the first wellbore 12A (e.g., before the piping 70reaches the wellhead of the first wellbore 12A).

Referring to FIG. 4, a non-limiting example of the mobile pump system 44may include a cab 76. The cab 76 may be a truck capable of attaching thetrailer 46 thereto (such as via a fifth wheel), so that the trailer 46may be hauled to and from the production site 10. The trailer 46 may bedetachable from the cab 76 so that it may be left at the job site, orthe trailer 46 may be an integrated part of the cab 76 (not detachabletherefrom). In some examples, the cab 76 is the power generator 52because the cab may fuel the electric motor and/or turbine and/ornatural gas fired reciprocating engine 50 used to drive the at least onepump 48.

Referring to FIG. 5, a top view of a non-limiting example of the mobilepump system 44 is shown, with the mobile pump system 44 including thetrailer 46, the at least one pump 48 having the electric motor and/orturbine and/or natural gas fired reciprocating engine 50, and the powergenerator 52. The power generator 52 may be connected to the at leastone pump 48 (e.g., the electric motor 50) to fuel the electric motorand/or turbine and/or natural gas fired reciprocating engine 50, suchthat the electric motor and/or turbine and/or natural gas firedreciprocating engine 50 may drive the at least one pump 48.

Referring to FIG. 6, a non-limiting example of the at least one pump 48is shown. The at least one pump 48 may be any pump suitable for pumpingthe positioning fluid 42 as previously described. In one example, the atleast one pump 48 may be an auger-style pump that includes an auger orimpeller 78 driven by the electric motor and/or the turbine and/ornatural gas fired reciprocating engine 50 to move the positioning fluid42 into the wellbore 12. The auger-style pump may provide certainadvantages, including allowing for a more precise control of flow rate,reduced maintenance, and ease of maintenance (based on the reducednumber and simplicity of components).

Referring to FIG. 7, the at least one pump 48, the electric motor and/orthe turbine and/or natural gas fired reciprocating engine 50, thegenerator 52, and/or other components (“controllable components”) of themobile pump system 44 may be controlled remotely by a controller 80. Asused herein, “remotely” refers to a geographic location separate fromthe controllable component. The at least one pump 48 may be controlledfrom the data monitoring station 68 or other location at the productionsite 10 (shown in FIG. 3), or the at least one pump 48 may be controlledoff-site (not at the production site 10). The at least one pump 48 maybe controlled by the controller 80 that is a portable computing device,such that the portable computing device may be moved between locationsand is still able to control the at least one pump 48. The portablecomputing device may be, for instance, a laptop computer, a tabletcomputer, or a smartphone. Thus, relevant data associated with themobile pump system 44 may be communicated to the controller 80 remotefrom the controllable component(s).

An exemplary graphical user interface (GUI) displayed on the controller80 is shown in FIG. 7, and a user may control the controllablecomponents by interacting with the GUI on the controller 80. The GUI mayallow the user to control various features of the controllablecomponents. Non-limiting examples include controlling the pump's 48 flowrate or the pressure of the at least one pump 48. The GUI may displaythe flow rate and pressure of the at least one pump 48. The GUI mayallow the user to turn the at least one pump 48 on or off. The GUI maydisplay the fill level of the fluid tank 54 or provide a status of theelectric motor and/or the turbine and/or natural gas fired reciprocatingengine 50, such as whether any issues are identified with the electricmotor and/or the turbine and/or natural gas fired reciprocating engine50. It will be appreciated that other aspects of the mobile pump system44 may be controlled by interacting with the GUI, and any suitablelayout of the GUI may be used. Multiple controllable components (e.g.,multiple pumps) may be controllable from the same controller 80.

Beyond providing the capability to adjust certain parameters of thesystem, the GUI may display on the controller various diagnostic andmonitoring information. As non-limiting examples, the GUI may displayelectric motor and/or the turbine and/or the natural gas firedreciprocating engine temperature, fluid levels, and pump revolutions perminute.

Referring to FIG. 8, a mobile pump system 82 is shown. The mobile pumpsystem 82 may include a trailer 84 attachable to a vehicle for movingthe trailer 84 to various locations. The mobile pump system 82 mayinclude a controller 86 mounted on the trailer 84, the controller 86 inelectrical communication with other components of the mobile pump system82 (e.g., an electrical transformer 88, a variable frequency drive 90, aheat exchanger 92, an electric motor 94, a pump 96, a secondary pump 98,and a secondary electric motor 100). The controller 86 may communicatecontrol signals to the other components to cause the other components toperform a predetermined action (e.g., activating or deactivating acomponent, changing a pump rate, changing a heat exchanger temperature,and the like).

The mobile pump system 82 may include an electrical transformer 88mounted on the trailer 84. The electrical transformer 88 may increase ordecrease a voltage from an external power source for use by one of thecomponents of the mobile pump system 82. This may allow components ofthe mobile pump system 82 to be powered by an external power source notincluded on the trailer 84 by electrically connecting the external powersource to the transformer 88, which may be electrically connected to theother components.

The mobile pump system 82 may include the variable frequency drive 90mounted on the trailer 84. The variable frequency drive 90 may includean electro-mechanical drive system to control motor speed and/or torqueof the electric motor 94 by varying motor input frequency and/orvoltage.

The mobile pump system 82 may include the heat exchanger 92 mounted onthe trailer 84 to regulate temperature of at least one of the othercomponents (e.g., the electric motor 94 and/or the pump 96), such thatthe component can operate more efficiently. The heat exchanger 92 mayfunction as a cooler to prevent a component of the mobile pump system 82from overheating.

The mobile pump system 82 may include the electric motor 94 mounted onthe trailer 84, the electric motor 94 as previously described herein.The mobile pump system 82 may also include the pump 96 a, 96 b (a singleor multiple pumps may be included) mounted on the trailer 84. The pump96 a, 96 b may include the features previously described herein inconnection with at least one pump 48. The pump 96 a, 96 b may be drivenby the electric motor 94.

With continued reference to FIG. 8 and referring to FIG. 11, the mobilepump system 82 may include a secondary pump 98 and/or a secondary motor100 (e.g., an electric motor) mounted on the trailer 84. The secondarypump 98 may include a triplex or quintuplex pump. The secondary pump 98may be configured for pumping fluid at higher pressure compared to thepump 96 a, 96 b of the mobile pump system 82. The secondary pump 98 maybe selectively activated in situations in which the mobile pump system82 is required to operate at a higher pressure. The secondary pump 98may be isolated from the pump 96 a, 96 b of the mobile pump system. Thesecondary motor 100 may drive the secondary pump 98. The pump 96 a, 96 band/or the secondary pump 98 may be in fluid communication with thewellbore 12 (see FIG. 2).

Referring to FIG. 9, a mobile pump system 102 may include any of thecomponents discussed in connection with the mobile pump system 82 fromFIG. 8 and may include any additional or alternative components ashereinafter described. The trailer 84 may include a connection portion104 configured to engage with an engagement portion of a cab (e.g., afifth wheel). The connection portion 104 may engage with a cab, suchthat the mobile pump system 102 may be transported by the cab to variouslocations, such as to and from a production site.

The mobile pump system 102 may include an inlet filter silencer 106mounted on the trailer 84 to reduce noise emitted by any of thecomponents included in the mobile pump system 102.

The mobile pump system 102 may include a turbine and/or a natural gasfired reciprocating engine 108 a, 108 b (a single or multiple turbinesand/or natural gas fired reciprocating engines may be included) mountedon the trailer 84 and connected to the pump 96 a, 96 b. The turbineand/or natural gas fired reciprocating engine 108 a, 108 b may beenclosed in a housing. The turbine and/or natural gas firedreciprocating engine 108 a, 108 b may be an on-board (on the trailer 84)turbine and/or natural gas fired reciprocating engine to generate poweron the trailer 84 for driving the pumps 96 a, 96 b. The turbine and/ornatural gas fired reciprocating engine 108 a, 108 b may be directlycoupled to the pump 96 a, 96 b via a gearbox 110 a, 110 b (a speedreduction mechanism may be included), which may include gear reductioncomponents. The turbine and/or natural gas fired reciprocating engine108 a, 108 b may be powered by using field gas (e.g., natural gas) e.g.,introduced to the turbine to spin the turbine blades to create power torotate the pump 96 a, 96 b. The power generated by the turbine and/orthe natural gas fired reciprocating engine 108 a, 108 b may drive thepump 96 a, 96 b. The turbine and/or natural gas fired reciprocatingengine 108 a, 108 b may be included in the mobile pump system 102 inaddition to or in lieu of the electric motor 94 a, 94 b shown in themobile pump system 82 shown in FIG. 8.

Referring to FIG. 10, a mobile pump system 112 may include all of thecomponents from the mobile pump system 102 of FIG. 9 with the followingadditions or alterations. The mobile pump system 112 may include a fueltank 114 (or multiple fuel tanks) mounted on the trailer. The fuel tank114 may include any type of fuel suitable to fuel any of the componentsof the mobile pump system 112. Non-limiting examples of suitable fuelsfor the fuel tank 114 include compressed natural gas (CNG), liquefiednatural gas (LNG), diesel fuel, gasoline, propane, butane, and othersuitable hydrocarbons and the like. The fuel tank 114 may be in fluidcommunication with any of the components of the mobile pump system 112capable of being fueled by the fuel contained in the fuel tank 114. Thefuel tank 114 may include any pumps, pipes, hoses, and/or valvesrequired to carry the fuel to the relevant components of the mobile pumpsystem 112.

The fuel tank 114 may be used as a backup fuel supply in the event of afuel supply interruption. A fuel supply interruption may include theinterruption of field gas (e.g., natural gas supplied directly from theproduction site at which the mobile pump system 112 is located) to themobile pump system 112. Inclusion of the fuel tank 114 on the trailer 84allows the mobile pump system 112 to continue operation even in theevent of such a fuel supply interruption, without the deployment of anemergency backup power supply to the production site.

The mobile pump system 112 may include a conditioning system 116configured to condition the gas from the fuel tank 114 or the field gassupplied to the mobile pump system 112. The conditioning system 116 mayinclude a gas heater to drop out solids and/or water from the gas andreturn it to the supply line. The conditioning system 116 may include atleast one filter to filter out impurities in the fuel that could causethe system to malfunction.

Referring to FIGS. 12 and 13, another non-limiting example of a mobilepump system 200 is shown. The mobile pump system 200 may include atleast one trailer 202 movable by a vehicle, such as a truck. The mobilepump system 200 may include a single trailer, as shown, but a mobilepump system including a plurality of trailers to mount the plurality ofpumps and the turbine and/or natural gas fired reciprocating engine (asdescribed hereinafter) is also contemplated. Certain components (e.g.,the pumps) of the mobile pump system described herein may be mounted toa first trailer while other of the components (e.g., the turbine and/ornatural gas fired reciprocating engine) of the mobile pump system may bemounted to a second trailer. As such, the mobile pump system 200 may bepositioned at a site for performing a pressure pumping applicationwithout permanently installing the mobile pump system 200 at the site. Aturbine and/or natural gas fired reciprocating engine 204 may be mountedto the trailer 202. The mobile pump system 200 may include a pluralityof pumps 206 a, 206 b, 208, 218, each mounted to the trailer 202. Thepumps may be in fluid communication with one another by a conduit 214.The conduit 214 may be configured to be placed in fluid communicationwith an outlet, which is in fluid communication with the intendeddestination of the fluid being pumped by the mobile pump system 200. Forexample, the conduit 214 may be configured to be placed in fluidcommunication with a wellbore in non-limiting scenarios in which fluidis being pumped into the wellbore by the mobile pump system 200.

The plurality of pumps 206 a, 206 b, 208, 218 may include at least onefirst pump 206 a, 206 b. In the non-limiting example of the mobile pumpsystem 200 shown in FIGS. 12 and 13, two first pumps 206 a, 206 b areincluded; however, the mobile pump system 200 may include a single firstpump or three or more first pumps. The first pump 206 a may be amulti-stage centrifugal injection pump (one example of which is shown inFIG. 14), each stage allowing for an increase in the flow rate and/orthe pressure pumped. The first pump 206 a may be a pressure-balancedpump, so as to reduce the torque loading on the first pump 206 a, 206 b.In one non-limiting example of a pressure-balanced pump, a twelve stagepump may include a fluid inlet or suction port, such that when the fluidenters the fluid inlet or suction port, the fluid is flowed to stages1-6. Before entering stages 7-12, the fluid may redirect around stages7-12 and enter stage 12, followed by stage 11, stage 10, stage 9, stage8, and stage 7, in that order, and discharge the fluid proximate towhere the fluid inlet or suction port is located. Such an arrangementmay create a more pressure load balanced pump, such that the torque fromoperation of the pumps is reduced. The reduced torque means that thesystem is not required to withstand high torques, leading to reduceddesign and maintenance costs. The first pump 206 a may be configured topump fluid at a flow rate as low as 1.5 bpm or as low as 2.5 bpm or aslow as 3.5 bpm. The first pump 206 a may be configured to pump fluid ata flow rate of up to 25 bpm, up to 30 bpm, up to 40 bpm, up to 50 bpm,up to 60 bpm, up to 70 bpm, or up to 80 bpm. The first pump 206 a may beconfigured to pump fluid at a flow rate of from 1.5-30 bpm, such as2.5-30 bpm or from 1.5-60 bpm, such as from 2.5-60 bpm. The first pump206 a may be configured to pump fluid at a pressure of 15,000 psi orgreater, such as 16,000 psi or greater, or 20,000 psi or greater.

The inclusion of the first pump 206 a as a multi-stage centrifugalinjection pump in combination with the positive displacement second pump208 (described hereinafter) allows for costs of including a multiplehigh-cost pressure displacement pumps capable of operating at relativelyhigher flow rates (those flow rates associated with the first pump 206 a) to be avoided.

The plurality of pumps 206 a, 206 b, 208, 218 may include at least onesecond pump 208. In the non-limiting example of the mobile pump system200 shown in FIGS. 12 and 13, one second pump 208 is included; however,the mobile pump system 200 may include multiple second pumps. The secondpump 208 may be a positive displacement pump. The positive displacementpump may be a reciprocating triplex or quintuplex pump (non-limitingexamples of which are shown in FIGS. 15 and 17). The second pump 208 maybe configured to pump fluid at a flow rate as low as 0.1 bpm. The secondpump 208 may be configured to pump fluid at a flow rate at or below 2.5bpm or below 1.5 bpm. The second pump 208 may be configured to pumpfluid at a flow rate of from 0.1-2.5 bpm or from 0.1-1.5 bpm. The secondpump 208 may be configured to pump fluid at a pressure of up to 15,000psi.

The first pump 206 a may have a higher flow rate capability and/or ahigher pumping pressure capability compared to the second pump 208. Thesecond pump 208 may have a lower flow rate capability and/or a lowerpumping pressure capability compared to the first pump 206 a . The flowrate capability and/or the pumping pressure capability of the first pump206 a and the second pump 208 may include an overlap. The first setpoint and/or the second set point (described hereinafter) may fallwithin the overlap.

With continued reference to FIGS. 12 and 13, the turbine and/or thenatural gas fired reciprocating engine 204 may be directly coupled tothe first pump 206 a, 206 b and/or the second pump 208. In somenon-limiting examples, the turbine and/or the natural gas firedreciprocating engine 204 may be directly coupled to the first pump 206a, 206 b. The turbine and/or the natural gas fired reciprocating engine204 may be directly coupled to the first pump 206 a, 206 b and/or thesecond pump 208 by a non-variable fixed ratio direct-coupled connection.The turbine and/or the natural gas fired reciprocating engine 204 may bedirectly coupled to the first pump 206 a, 206 b and/or the second pump208 by a direct-coupled gear connection including a speed reducer 210.The direct coupling eliminates the need for a transmission, thuseliminating moving parts that may require maintenance or result inadditional operating costs. In some non-limiting examples, the turbineand/or the natural gas fired reciprocating engine 204 is connected tothe speed reducer 210, which is connected to a plurality of first pumps206 a, 206 b. The turbine and/or the natural gas fired reciprocatingengine 204 may be powered using field gas, such that the mobile pumpsystem 200 has a lower carbon footprint compared to systems using dieselengines, for example. The use of a turbine and/or natural gas firedreciprocating engine 204 on the mobile pump system 200 (as opposed to,for example, a diesel engine) allows the mobile pump system 200 tooperate at lower decibels. The mobile pump system 200, when inoperation, may emit less than 85 decibels, less than 80 decibels, lessthan 75 decibels, less than 70 decibels, or less than 65 decibels(compared to the at least 115 decibels emitted by certain existingsystems utilizing a diesel engine.)

With continued reference to FIGS. 12 and 13, the mobile pump system 200may include an electric motor 212. The electric motor 212 may be inelectrical communication with the turbine and/or the natural gas firedreciprocating engine 204, such that that the turbine and/or the naturalgas fired reciprocating engine 204 provides electrical energy to theelectric motor 212. The electric motor 212 may be connected to thesecond pump 208 to power the second pump 208.

With continued reference to FIGS. 12 and 13, the mobile pump system 200may include a fluid storage tank mounted on the trailer 202, and thefluid storage tank may be filled with a fluid to be pumped by the mobilepumping system 200. In some non-limiting examples, a fluid storage tankmay be positioned at the site off of the trailer 202, in addition to orin lieu of the fluid storage tank mounted on the trailer 202.

The mobile pump system 200 may include a third pump 218 mounted on thetrailer 202. The third pump 218 may be in fluid communication with atleast one of the fluid storage tank, the first pump 206 a, 206 b, andthe second pump 208 by the conduit 214. The third pump 218 may beconfigured to pump fluid from the fluid storage tank to at least one ofthe first pump 206 a, 206 b and the second pump 208. The third pump 218may be a volute-type centrifugal pump and may pump fluid from the atleast one of the fluid storage tank to the first pump 206 a, 206 band/or the second pump 208 by the conduit 214 at a flow rate of from0-3.5 bpm, such as 0-2.5 bpm and at a pressure of up to 15,000 psi.

With continued reference to FIGS. 12 and 13, the mobile pump system 200may include a control system 216 comprising at least one processorprogrammed or configured to control at least one of the components ofthe mobile pump system 200 (and may be in electrical communicationtherewith). The control system 216 may receive input data from a user,such as via a graphical user interface, or may collect data from othersources, such at least one pressure sensor, flow sensor, temperaturesensor, and the like, to communicate instructions to the components ofthe mobile pump system 200 (e.g., the first pump 206 a, 206 b, thesecond pump 208, and/or the turbine and/or the natural gas firedreciprocating engine 204). The control system 216 may communicate withthe components of the mobile pump system 200 to control, for example, arotational speed of the turbine and/or the natural gas firedreciprocating engine 204, a flow rate of the first pump 206 a, 206 band/or the second pump 208, and a pumping pressure of the first pump 206a, 206 b and/or the second pump 208. The control system 216 may use anadvanced control algorithm to generate instructions to control thecomponents of the mobile pump system 200. The advanced control algorithmmay consider at least one of the following: pump properties, fluidproperties, on-site atmospheric properties, and the like, to enable thecontrol system 216 to generate the instructions to control thecomponents of the mobile pump system 200.

The control system 216 may include an electronic governor configured tocontrol at least one of the rotational speed of the turbine and/or thenatural gas fired reciprocating engine 204, the flow rate of the firstpump 206 a, 206 b and/or the second pump 208, and the pumping pressureof the first pump 206 a, 206 b and/or the second pump 208. The controlsystem 216 may communicate the instructions for the components of themobile pump system 200 to the electronic governor to cause theelectronic governor to communicate with the components to cause theinstructions to be effected by the components. The control system 216enables the mobile pump system 200 to control small incrementaladjustments in the rotational speed of the turbine and/or the naturalgas fired reciprocating engine 204, the flow rate of the first pump 206a, 206 b and/or the second pump 208, and the pumping pressure of thefirst pump 206 a, 206 b and/or the second pump 208 without transmissionor gear-based controls, which lack the capability for the highly precisecontrols of the mobile pump system 200.

The control system 216 may receive set point data from a user thatspecifies a desired a rotational speed of the turbine and/or the naturalgas fired reciprocating engine 204, a flow rate of the first pump 206 a,206 b and/or the second pump 208, and/or a pumping pressure of the firstpump 206 a, 206 b and/or the second pump 208, such as by the userentering the set point data into a graphical user interface. Based onthe user specifying a desired rotational speed of the turbine and/or thenatural gas fired reciprocating engine 204, the control system 216 mayautomatically generate instructions (based on the advanced controlalgorithm, for example) to cause the first pump 206 a, 206 b and/or thesecond pump 208 to operate at a flow rate and/or a pumping pressure,such that the desired rotational speed may be changed or maintained.Based on the user specifying a flow rate of the first pump 206 a, 206 band/or the second pump 208, the control system 216 may automaticallygenerate instructions (based on the advanced control algorithm, forexample) to cause the first pump 206 a, 206 b and/or the second pump 208to operate at a pumping pressure and/or the turbine and/or the naturalgas fired reciprocating engine 204 to operate a rotational speed, suchthat the desired flow rate may be maintained. Based on the userspecifying a pumping pressure of the first pump 206 a, 206 b and/or thesecond pump 208, the control system 216 may automatically generateinstructions (based on the advanced control algorithm, for example) tocause the first pump 206 a, 206 b and/or the second pump 208 to operateat a flow rate and/or the turbine and/or the natural gas firedreciprocating engine 204 to operate a rotational speed, such that thedesired pumping pressure may be maintained. Therefore, a deviation ofthe actual data value from the set point data value may cause thecontrol system 216 to generate instructions to the relevant componentsto cause the components of the mobile pump system 200 to automaticallyadjust to return to the set point value.

The control system 216 may be configured to communicate (e.g., via theelectronic governor) with the turbine and/or the natural gas firedreciprocating engine 204 to control the rotational speed of the turbineand/or the natural gas fired reciprocating engine 204. The controlsystem 216 may adjust the rotational speed of the turbine and/or thenatural gas fired reciprocating engine 204 by an incremental amount aslow as the rpm required to change the flow rate by 0.1 bpm.

The control system 216 may be configured to communicate (e.g., via theelectronic governor) with the first pump 206 a, 206 b and/or the secondpump 208 to control the flow rate thereof. The control system 216 mayadjust the flow rate of the first pump 206 a, 206 b and/or the secondpump 208 by an incremental value as low as 0.1 bpm. In some non-limitingexamples, the control system 216 may automatically adjust the flow rateof the first pump 206 a, 206 b and/or the second pump 208 to reach ormaintain a pressure pumping set point value specified by the user forthe first pump 206 a, 206 b and/or the second pump 208.

The control system 216 may be configured to communicate (e.g., via theelectronic governor) with the first pump 206 a, 206 b and/or the secondpump 208 to control the pumping pressure thereof. In some non-limitingexamples, the control system 216 may automatically adjust the pumpingpressure of the first pump 206 a, 206 b and/or the second pump 208 toreach or maintain a flow rate set point value specified by the user forthe first pump 206 a, 206 b and/or the second pump 208.

With continued reference to FIGS. 12 and 13, the control system 216 maybe configured to perform a “hand-off” operation. The hand-off operationmay include the control system 216 being configured to activate thesecond pump 208, with the first pump 206 a, 206 b deactivated, with aflow rate of the mobile pump system 200 below a first set point to causethe second pump 208 to pump a pumping fluid from the fluid storage tankto the outlet. The control system 216 may be configured to, in responseto the flow rate of the mobile pump system 200 reaching the first setpoint, activate the first pump 206 a, 206 b to cause the first pump 206a, 206 b to pump the pumping fluid. The control system 216 may beconfigured to deactivate the second pump 208, with the first pump 206 a,206 b still activated, in response to the flow rate of the mobile pumpsystem 200 reaching a second set point, with the second set pointgreater than or equal to the first set point. In some non-limitingexamples, the control system 216 may cause the pumping fluid to bepumped to the outlet by the second pump 208 and not the first pump 206a, 206 b with the flow rate of the mobile pump system 200 below thefirst set point, and the pumping fluid to be pumped to the outlet by thefirst pump 206 a, 206 b and optionally the second pump 208 with the flowrate of the mobile pump system at or above the first set point.

In one non-limiting illustrative example, the mobile pump system 200 mayinitially be deactivated, having a flow rate associated therewith of 0bpm. The mobile pump system 200 may be activated to begin pumping thepumping fluid, and the control system 216 may activate the second pump208 to begin the pumping application. The second pump 208 may pump thepumping fluid with the first pump 206 a, 206 b deactivated at lower flowrates (below the first set point and/or below the minimum flow ratepumping capability of the first pump 206 a, 206 b). Thus, the third pump218 may flow the pumping fluid from the fluid storage tank to the secondpump 208 when the flow rate of the mobile pump system 200 is below thefirst set point, such that the second pump 208 moves the pumping fluidto the outlet. Upon the flow rate of the mobile pump system 200 reachingthe first set point, the control system 216 may activate the first pump206 a, 206 b to cause the first pump 206 a, 206 b to pump pumping fluid.Thus, the third pump 218 may flow the pumping fluid from the fluidstorage tank to the first pump 206 a, 206 b when the flow rate of themobile pump system 200 reaches the first set point, such that the firstpump 206 a, 206 b moves the pumping fluid to the outlet. At a second setpoint equal to or higher than the first set point, the control system216 may deactivate the second pump 208 so that only the first pump 206a, 206 b (of the first 206 a, 206 b and second pumps 208) is movingpumping fluid to the outlet. The first pump 206 a, 206 b may pump thepumping fluid at a flow rate above the capabilities of the second pump208. In some non-limiting examples, the first set point is equal to thesecond set point, such that as the control system 216 activates thefirst pump 206 a, 206 b, the second pump 208 is deactivated (at the sameset point). In some non-limiting examples, the second set point ishigher than the first set point such as between the first set point andthe second set point, the first pump 206 a, 206 b and the second pump208 work in tandem to flow pumping fluid to the outlet.

With continued reference to FIGS. 12 and 13, the control system 216 maybe configured to initiate a start-up protocol to run the mobile pumpsystem 200. The start-up protocol may include the control system 216causing the second pump 208 to be activated, while the first pump 206 a,206 b remains deactivated, until a flow rate effected by the mobile pumpsystem 200 is at least 1.5 bpm. The control system 216 may be configuredto activate the first pump 206 a, 206 b, while the second pump 208 isstill activated, once the flow rate effected by the mobile pump system200 is at a first set point. The first set point may be at least 1.5bpm, such as at least 2.5 bpm. The first set point may range from1.5-3.5 bpm, such as from 1.5-2.5 bpm or 2.5-3.5 bpm. Further, thecontrol system 216 may be configured to deactivate the second pump 208,while the first pump 206 a, 206 b is still activated, once the flow rateeffected by the mobile pump system is at a second set point. The secondset point may range from 1.5-3.5 bpm, such as from 1.5-2.5 bpm. Thesecond set point may be equal to or higher than the first set point. Theflow rate associated with the second pump 208 may be phased out as theflow rate associated with the first pump 206 a, 206 b increases.

As illustrated by the above-described operation of the control system216 controlling activation and deactivation of the first pump 206 a, 206b and the second pump 208, the mobile pump system 200 has been designedto handle ancillary pressure pumping applications associated withhydraulic fracturing, which often require the full range of lowrate/high pressure pumping applications to high rate/high pressurepumping applications. The combination of the first pump 206 a, 206 b andthe second pump 208 on the mobile pump system 200 enables these pumpingparameters to be achieved using a mobile system with lower capitalcosts. Further, the above-described activation and deactivation of thefirst pump 206 a, 208 and the second pump 208 (e.g., in the operatingorder described) allows for the second pump 208 capable of operating atlower flow rates to hand-off the pumping application to the first pump206 a, 206 b, which is capable of operating at higher flow rates.

The utilization of the first pump 206 a, 206 b in the mobile pump system200, which may be a multi-stage centrifugal injection pump, at pumprates above 1.5 bpm, such as above 2.5 bpm, above 3.5 bpm, or above 5bpm allows for fracture propagation to occur more efficiently comparedto a pumping system only including a positive displacement pump. Themulti-stage centrifugal injection pump allows for an almostinstantaneous response to formation breakdown and is capable ofincreasing flow rate relatively more seamlessly to achieve a targetpressure. Thus the combination of the first pump 206 a, 206 b with thesecond pump 208 of a different style on the trailer 202 allow for thepump more suitable for the particular pumping application (or stagethereof) to be seamlessly used on the mobile pumping system 200.

The mobile pump system 200 may include a fuel buffering system, whichmay be positioned to remove undesired liquids, solids, and other debrisfrom the chamber of the turbine 204 and/or the natural gas firedreciprocating engine and/or to prevent such products from entering thechamber of the turbine and/or the natural gas fired reciprocating engine204.

The turbine and/or natural gas fired reciprocating engine 204 maygenerate excess power, in excess of the power needed to power the mobilepump system 200, such that the excess power may be transferred to otheron-site locations to power other on-site components. For example, theexcess power may be directed to other on-site needs, such as wirelineneeds, water transfer needs, and the like. The turbine 204 may include ashaft on a side opposing the side of the mobile pump system 200 whichmay rotate a standard electric motor and/or generator and send theexcess power (at a specified wattage) through a cable to the otheron-site components to provide the necessary power requirement.

The mobile pump system 200, may be positioned on a pump site to performa pressure pumping application thereon. The pressure pumping applicationmay be an oil/gas-field or non-oil/gas-field-related application.

The mobile pump system 200 positioned on a pump site may be used toperform the previously-described “plug-and-perf” method in which a plugis positioned in a lateral of a wellbore using the fluid pumped into thewellbore by the mobile pump system 200.

The mobile pump system 200 positioned on a pump site may be used toperform a toe prep application. Toe prep applications prepare the wellfor the commencement of fracture stimulation operations. Toe prepsinvolve establishing an initial pathway for fracture propagation intothe reservoir from the well, thereby allowing fluid communication frominside the wellbore into the target formation. Toe preps may involveshifting casing sleeves through building pressure using fluid pumped bythe mobile pump system 200 to provide the pathway for fluid to exit thecasing into the formation. Toe preps may also involve tubing-conveyedperforating (TCP) and other wireline conveyed perforating, for example,in conjunction with the fluid pumped by the mobile pump system 200.Injection tests, like Diagnostic Fracture Injection Tests (DFIT), arecommonly performed at the beginning of fracture stimulation operationsand can be designed for low-rate/high pressure and/or high-rate/highpressure through the range of capabilities of the mobile pump system200.

The mobile pump system 200 may be positioned at an agricultural site tomove water or other fluid for an agricultural application. The mobilepump system 200 may be positioned at a mining site to move water orother fluid for a mining application, such as dewatering and orsupplying water in coal and/or precious metal mining operations.

The mobile pump system 200 positioned on a pump site may be used toperform a drill-out application. Drill-out applications are performedafter a well is fracture stimulated. During multi-stage fracturestimulation operations, plugs are placed in the lateral for zonalisolation prior to the performance of additional fracture stimulationstages. Typically plugs are spaced 150 ft to 300 ft apart in a wellborebut are not limited to those distances. At a time after fracturestimulations have been completed, these plugs are drilled out. A bit ormill is commonly placed at the end of a tubing string or coiled tubing,for instance, and is rotated to drill up each plug in succession. Duringdrill-out operations, fluid may be circulated to keep the wellbore cleanand to carry cuttings and debris out of the wellbore. This fluid iscirculated by the mobile pump system 200 at potentially very low rates,such as 1-2 bpm (or lower), and higher rates, such as 8-9 bpm (orhigher), depending on tubing and casing sizes, for instance, orcondition of the well as regards sand from fracture stimulationoperations and debris.

The mobile pump system 200 positioned on a pump site may be used toperform an industrial purging application. In industrial purging, pipingassociated with plant or factory operations, for instance, may requiretreatments that can include flushing debris, cleansing the system, orclearing blockages utilizing a fluid pumped by the mobile pump system200.

The mobile pump system 200 positioned on a pump site may be used toperform a pipeline pressure testing application. Before pipelines areplaced into service, pipeline pressure testing operations are utilizedto assure that the system safely meets the maximum allowable operatingpressures (MAOP). Additionally, pipelines are tested at regularintervals to assure safe operations with regard to pressure. Fluid ispumped into the pipeline(s) by the mobile pump system 200 and held at adesignated pressure for a determined period of time. The mobile pumpsystem's 200 precise controls can achieve designed pressures moreaccurately than conventional pumps, as in those involving diesel enginesand transmissions.

The mobile pump system 200 positioned on a pump site may be used toperform a hydro-blasting application. Whereas sand blasting and dryblasting introduces particulate matter into the air, hydro-blastingutilizes no abrasives but utilizes fluid pressure (as in pressurewashing) instead. Fluid pumped at a variety of pressures by the mobilepump system 200 with its precise controls can be utilized in a varietyof applications, such as stripping old paint from metal surfaces, forexample.

The mobile pump system 200 may perform a pressure pumping application byactivating the second pump 208, with the first pump 206 a, 206 bdeactivated, until a flow rate effected by the mobile pump system 200 isat least 1.5 bpm; and activating the first pump 206 a, 206 b, while thesecond pump 208 is still activated, once the flow rate effected by themobile pump system 200 is at a first set point, the first set pointbeing at least 1.5 bpm. Performing the pressure pumping application mayfurther include deactivating the second pump 208, while the first pump206 a, 206 b is still activated, once the flow rate effected by themobile pump system 200 is at a second set point, the second set pointbeing equal to or higher than the first set point.

Although the invention has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred embodiments, it is to be understood that suchdetail is solely for that purpose and that the invention is not limitedto the disclosed embodiments, but, on the contrary, is intended to covermodifications and equivalent arrangements that are within the spirit andscope of the appended claims. For example, it is to be understood thatthe present invention contemplates that, to the extent possible, one ormore features of any embodiment can be combined with one or morefeatures of any other embodiment.

The invention claimed is
 1. A mobile pump system, comprising: at leastone trailer movable by a vehicle; a plurality of pumps comprising afirst pump and a second pump, wherein the first pump and the second pumpare each mounted to the at least one trailer, wherein the first pump andthe second pump are each in fluid communication with an outletconfigured to flow a fluid from the mobile pump system to a destinationand with a fluid source configured to hold a pumping fluid; a powersource mounted to the at least one trailer and directly coupled to thefirst pump and/or the second pump, wherein the power source comprises aturbine and/or a natural gas fired reciprocating engine; and a controlsystem configured to: activate the second pump, with the first pumpdeactivated, with a flow rate of the mobile pump system below a firstset point to cause the second pump to pump the pumping fluid; inresponse to the flow rate of the mobile pump system reaching the firstset point, activate the first pump to cause the first pump to pump thepumping fluid; and deactivate the second pump, with the first pumpactivated, in response to the flow rate of the mobile pump systemreaching a second set point, wherein the second set point is greaterthan or equal to the first set point.
 2. The mobile pump system of claim1, wherein the first pump is configured to pump fluid at a flow rate aslow as 1.5 bpm and at a flow rate of up to 30 bpm, and wherein thesecond pump is configured to pump fluid a flow rate as low as 0.1 bpm.3. The mobile pump system of claim 1, wherein the first pump comprises amulti-stage centrifugal injection pump.
 4. The mobile pump system ofclaim 1, wherein the first pump comprises a pressure-balanced pump. 5.The mobile pump system of claim 1, wherein the second pump comprises apositive displacement pump.
 6. The mobile pump system of claim 5,wherein the positive displacement pump is a reciprocating triplex orquintuplex pump.
 7. The mobile pump system of claim 1, wherein thecontrol system comprises an electronic governor configured to control atleast one of a rotational speed of the power source, a flow rate of thefirst pump and/or the second pump, and a pumping pressure of the firstpump and/or the second pump.
 8. The mobile pump system of claim 7,wherein the electronic governor is configured to adjust the flow rate ofthe first pump and/or the second pump by an incremental amount as low as0.1 bpm.
 9. The mobile pump system of claim 1, wherein the power sourceis directly coupled to the first pump, wherein the direct couplingcomprises a non-variable, fixed ratio direct-coupled connection or adirect-coupled gear connection including a speed reducer.
 10. The mobilepump system of claim 1, wherein the second pump is powered by anelectric motor receiving power generated by the power source.
 11. Themobile pump system of claim 6, wherein the control system is configuredto initiate a start-up protocol by: activating the second pump, with thefirst pump deactivated, until the flow rate of the mobile pump system isat least 1.5 bpm; and activating the first pump, while the second pumpis still activated, once the flow rate of the mobile pump system is atthe first set point, wherein the first set point is at least 1.5 bpm.12. The mobile pump system of claim 1, wherein the mobile pump system isnot permanently installed at a site for performing a pressure pumpingapplication.
 13. The mobile pump system of claim 1, wherein the powersource is operated using field gas.
 14. The mobile pump system of claim1, wherein the first pump and/or the second pump are configured to pumpfluid at a pressure of 15,000 psi or greater.
 15. The mobile pump systemof claim 1, further comprising a fluid storage tank mounted to the atleast one trailer and a third pump mounted to the at least one trailerand in fluid communication with the fluid storage tank, the first pump,and the second pump, wherein the third pump is configured to pump fluidfrom the fluid storage tank to the first pump and/or the second pump.16. The mobile pump system of claim 1, wherein the pumping fluid ispumped to the outlet by the second pump and not the first pump with theflow rate of the mobile pump system below the first set point, and thepumping fluid is pumped to the outlet by the first pump and optionallythe second pump with the flow rate of the mobile pump system at or abovethe first set point.
 17. A method for performing a pressure pumpingapplication, comprising: positioning the mobile pump system of claim 1on a pump site.
 18. The method of claim 17, further comprising:activating the second pump, with the first pump deactivated, until theflow rate of the mobile pump system is at least 1.5 bpm; and activatingthe first pump, while the second pump is still activated, once the flowrate of the mobile pump system is at the first set point, wherein thefirst set point is at least 1.5 bpm.
 19. The method of claim 18, furthercomprising: deactivating the second pump, while the first pump is stillactivated, once the flow rate flow rate of the mobile pump system is atthe second set point.
 20. A mobile pump system, comprising: a trailermovable by a vehicle; a plurality of pumps comprising a first pump and asecond pump, wherein the first pump and the second pump are each mountedto the trailer, wherein the first pump and the second pump are each influid communication with an outlet configured to flow a pumping fluidfrom the mobile pump system to a destination and configured to be influid communication with a fluid storage tank configured to hold thepumping fluid, wherein the first pump comprises a pressure-balancedmulti-stage centrifugal injection pump, wherein the second pumpcomprises a reciprocating triplex or quintuplex positive displacementpump; a power source mounted to the trailer and directly coupled to thefirst pump, wherein the power source comprises a turbine and/or anatural gas fired reciprocating engine, wherein the direct couplingcomprises a non-variable, fixed ratio direct-coupled connection or adirect-coupled gear connection including a speed reducer; a third pumpmounted to the trailer and configured to be placed in fluidcommunication with the fluid storage tank, wherein the third pump is influid communication with the first pump and the second pump, wherein thethird pump is configured to pump the pumping fluid from the fluidstorage tank to the first pump and/or the second pump and a controlsystem configured to: activate the second pump, with the first pumpdeactivated, with a flow rate of the mobile pump system below a firstset point to cause the third pump to pump the pumping fluid from thefluid storage tank to the second pump which is configured to pump thepumping fluid to the outlet; in response to the flow rate of the mobilepump system reaching the first set point, activate the first pump tocause the third pump to pump the pumping fluid from the fluid storagetank to the first pump which is configured to pump the pumping fluid tothe outlet; and deactivate the second pump, with the first pumpactivated, in response to the flow rate of the mobile pump systemreaching a second set point, wherein the second set point is greaterthan or equal to the first set point.